rp2040: Support CanBoot as bootloader

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

src/rp2040/main.c

@@ -6,6 +6,7 @@
 
 #include <stdint.h> // uint32_t
 #include "board/misc.h" // bootloader_request
+#include "generic/armcm_reset.h" // try_request_canboot
 #include "hardware/structs/clocks.h" // clock_hw_t
 #include "hardware/structs/pll.h" // pll_hw_t
 #include "hardware/structs/resets.h" // sio_hw
@@ -45,6 +46,7 @@ DECL_INIT(watchdog_init);
 void
 bootloader_request(void)
 {
+    try_request_canboot();
     // Use the bootrom-provided code to reset into BOOTSEL mode
     reset_to_usb_boot(0, 0);
 }